Azo dyestuffs and process for preparing the same



i atented Dec. 4, 1928.

UNITED STATES PATEN'T OFFICE.

DYESTUFF CORPORATION, OF NEW YORK, Y., A CORPORATION or DELAWARE.

AZO DYESTUFFS AND PROCESS FOP, PREPARING THE SAME.

No Drawing. Application filed December 21, 1926, Serial No. 156,259, and in Germany December 23, 1925.

wherein R stands for CH 'COOH or )O-alkyl. The dyestuffs thus obtained wool yellowisht brownish-red tints, ich, by after-chroniing, change to bluishr to claret-red shades of excellent propero fulling, potting and light. ie following example serves to illustrate z invention but is not intended to limit it t iereto, all parts being by weight:

The diazo compound obtained from 154 parts of -nitro-2-amino-l-phenol, 300 parts ct hydrochloric acid of B. and 69 parts of sodium nitrite is run into a solution of parts of 1(2-hydroxy-3-carboxy-5-sul enyl)-3-methyl-5-pyrazolone in an exw of sodium carbonate or sodium acetate. The dyestufi thus obtained is salted out and Ki: isolated in known manner. It has the probable formula forms when dry a brown powder and dyes wool a brownish-yellow tint, which on ino-l-phenol by the 5-nitro-4-chloro-2-aminol-phenol, and the 1-(2'-oXy-3-carboxy-5- sulfophenyl) r3-methyl-5-pyrazolone by the l- (2'-oXy-3-carboxy-5-sulfophenyl) -5-pyrazolone-3-carboxylic acid or by a 1-(2-oxy-3'- carboxy-5'-sulfophenyl) -5-pyrazolone-3 -carboxylic acid ester. I

1 claim: 7 J

1. The process'for preparing new azo dyestufis which consists in diazotizing a compound of the following formula:

OaN

R C N on 00011 l g soar wherein R represents: CH COOH or COO.alkyl.

2. The process for preparing new azo dyestuffs which consists in diazoti'zing 5-nitro- 2-amino-1-phenol of the following constitution:

and in coupling the diazo compound thus obtained with a compound of the following constitution wherein R represents: -CH COOH or COO.alkyl.

3. The process for preparing a new azo dyestufi which consists in diazotizing 5-nitro- 2-amino-1-phenol of the following constitution and in coupling the diazo compound thus obtained with a compound of the following constitution:

CH C N 0H coon l N on,-o

wherein X represents hydrogen or chlorine 0 and R stands for CH -COOH or COO.alkyl.

general formula:

' 5. As new products 5120 dyestuffs of the general formula OzN wherein R stands for GH -COOH or 40 COO.alkyl.

6.- As a new product the azo dyestufi of the following formula:

til

SOxH

OaN-

' 7. As new products azo dyestuflfs of the wherein X represents hydrogen or chloride.

In testimony whereof, I afiix my signature HEINZ EICHWEDE. 

